An ongoing challenge in the field of gene therapy and vaccine research is to generate liquid virus formulations which are stable for longer periods of time within a useful temperature range, such as from about 2° C. to about 8° C. Adenovirus vectors are currently considered one of the leading approaches for gene delivery/therapy. Because of the great potential for adenoviruses in the field of gene therapy, there remains a need for virus formulations that are suitable for human parenteral use, and have a 1-2 year shelf-life at 2-8° C. Although the U.S. military has developed live adenovirus vaccines for human use, they were lyophilized formulations delivered as oral dosage forms in enteric coated capsules (Chanock, et al., 1966, J. Am. Med. Assoc. 195: 151-158; Griffin, et al., 1970, Arch. Intern. Med. 125: 981-986; Top, et al., 1971, J. Infect. Dis. 124: 148-154). The excipients used in these early lyophilized formulations (gelatin, skim milk, human serum albumin) make these lyophilized formulations very unattractive for human parenteral administration. Despite reports on the structure and characterization of adenoviruses, there has been little published on the development of stabilization and formulation of adenovirus for parenteral administration in humans. Furthermore, most of the formulation work concerns lyophilized rather than aqueous formulations, presumably because the prospects for a stable liquid formulation seemed rather poor.
There are some limited reports of liquid formulations of adenovirus with stability data.
WO99/41416 discloses virus formulations which contain glycerol, sodium phosphate, Tris, sucrose, MgCl2, and polysorbate 80. The most stable formulation reported lost 0.52 logs of infectivity in one year at 4 C.
WO98/02522 (see also U.S. Pat. No. 6,451,256) discloses virus formulations with concentrations of sucrose from about 0.75M to 1.5M sucrose. Such a formulation would not be acceptable for human parenteral use.
Nyberg-Hoffman et al. (1999, Nature Medicine 5 (8): 955-956) disclose frozen liquid adenoviral formulations which contain Tris, sucrose and MgCl2.
Croyle et al. (1998, Pharm. Dev. Technol. 3 (3): 373-383) disclose lyophilized, frozen liquid and liquid virus formulations that contain Tris and phosphate buffered solutions with high concentrations of sucrose, trehalose or sorbitol/gelatin.
Croyle et al. (2001, Gene Therapy 8:1281-1290) show enhanced stability of liquid adenovirus formulations which comprise a cyclodextrin-based excipient.
Therefore, the need remains for the development of a recombinant virus liquid formulation that is stable for approximately 1-2 years at 2-8° C. and compatible with parenteral administration. Such a liquid formulation offers advantages such as lower overall cost, decreased development time and ease of use for the customer. The present invention addresses and meets these needs by disclosing improved recombinant virus liquid formulations which show enhanced stability for longer periods of time at temperatures in the range of 2-8° C.